The present invention is directed to method and apparatus for use in application of rubber ribbon material for the formation of tire tread on a substrate such as a tire carcass. More particularly, the present invention is directed to method and apparatus employed in conjunction with a tire building machine such as shown and described in U.S. Pat. No. 3,177,918 enabling the deposition of elastomeric material upon a substrate in a controlled fashion in accordance with a predefined tread profile. In carrying out the invention, a programmed is employed having principally; a micro-computer, a floppy disk and a keyboard.
By means of the present invention, it becomes possible to utilize current micro-processor technology enabling readily attainable changes to a finished tread profile by associated software modifications rather then hardware changes.
In the past, other systems known to the applicant, for example, U.S. Pat. No. 3,308,000 have been employed for controlling the application of the elastomeric material to a substrate. In this arrangement a tire tread winding apparatus employs a mechanically controlled arrangement for applying elastomeric ribbon to a tire casing. However, the approach disclosed in this prior art is purely mechanical and employs a mechanical programmer and associated spin revolution counter.
Also familiar to the applicant is U.S. Pat. No. 3,843,482 which is directed to a tire tread winding machine employing a tape for controlling the amount of spin of the rubber ribbon applicator assembly and also the amount of azimuth displacement for ribbon thickness control.
Other patents known to applicant further illustrate well known approaches for controlling the movement of a tire tread programmer. However, in no instance has the prior art defined a combination in which the use of an interface with a tread application apparatus is such, that the instantaneous tire spin rotational position forms the basis of a series of digital commands enabling extremely precise digitally controlled simultaneous transverse motion of the tire.
The prior systems have employed apparatus for tread application which have utilized additional variables of time, tire rotation velocity, or template sensing. By eliminating these variables, errors associated in their measurement and control have been eliminated. The present invention provides tire transverse position control directly as a programmed function of tire rotational position.